James Lin

My name is James and I will be working on the ALD and IC Packaging this semester :3

ALD Project Proposal: https://docs.google.com/document/d/1hN6o0-Mjtj6w6XVKbcjDsQGZm-uqVoWmuRubTbs2fYQ/edit?usp=drive_link

Packaging Project Proposal: https://docs.google.com/document/d/1mPezRVWu7PNa3ggTOlxjDEdb9D6B84CEXgIU-5ACNHs/edit?usp=drive_link

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Weekly Update #4:

ALD:

Progress:

• Grinded out design for delivery storage, some major design elements and specs:

  • Previously unused 1/2" section removed to prevent precursor mixing

  • Box made of 4 piece 1.6mm thick bent sheet metal

    • Bolted together with M3 screws

  • Manifold supported by ALD valve collar with 3/8"-16 U bolts mounted to box ceiling

  • Single hinge and latch using #6 screws

  • Mounts to 8020 stand with M5 screws

  • Cutouts for:

    • Inlet and outlet for carrier gas and precursors

      • 1/4" steel tubes wrapped with heat tape

    • 3 sets of heat tape and thermocouple

      • 1 for manifold and outlet line

      • 2 for TMIn and TDMSn ampules

    • ALD Valves power and control wires

    • ALD Valve N2 supply

    • Exhaust for KF40 bulkhead flange

    • Vent holes on 2 sides for exhaust airflow

• Submitted safety review of earlier prototype to Matt

• BOM:

Item	Supplier	Link	Quantity	Price	Ordered
Sheet metal	Send Cut Send		1
1/4" VCR Caps	Swagelok	https://products.swagelok.com/en/c/caps/p/SS-4-VCR-CP?q=:relevance:connection1Size:1%2F4+in.:connection1Type:VCR%C2%AE+Metal+Gasket+Face+Seal+Fitting	3	$47.7
1/4" VCR Gasket	Swagelok	https://products.swagelok.com/en/c/gaskets/p/SS-4-VCR-2	20	$38.00
1/4" FVCR to 1/4" Tube	Swagelok	https://products.swagelok.com/en/c/straights/p/SS-4-WVCR-6-400	1	$50.60
U bolts, 1-1/8" ID	McMaster	https://www.mcmaster.com/8880T955/	3	$5.64
Hinge	McMaster	https://www.mcmaster.com/1586A34/	1	$7.15
Latch	McMaster	https://www.mcmaster.com/1766A2/	1	$15.20
10-32 Screws, 3/8" long	McMaster	https://www.mcmaster.com/91251A340/	6	$14.86 (1 pack x100)
10-32 Drop in T nuts	McMaster	https://www.mcmaster.com/4976N25/	6	$4.88 (2 packs x10)
M3 screws	McMaster	https://www.mcmaster.com/91290A113/	64	$12.52 (1 pack x100)
M3 nylon lock nuts	McMaster	https://www.mcmaster.com/90576A102/	64	$4.82 (1 pack x100)
#6 screws, countersunk	McMaster	https://www.mcmaster.com/91263A514/	6	$8.26 (1 pack x25)
#6 screws, flat head	McMaster	https://www.mcmaster.com/91251A146/	6	$11.90 (1 pack x100)
#6 nylon lock nuts	McMaster	https://www.mcmaster.com/90631A007/	12	$3.93 (1 pack x100)

Struggles:

• balancing time with school work to get design finished

• we planned to order last Friday but wasn't able to get that ready in time

To do for this week:

• Confirm inlet and outlet configuration

• Make any final adjustments to sheet metal

• Finalize BOM and order everything before Tuesday

  • still need to set up a Send Cut Send Quote

• Work on presentation

Packaging

Progress:

• Informed Icey about the recommended 3 micron AL pad thickness from this article

  • https://lnf-wiki.eecs.umich.edu/wiki/Wire_bonding#Design_considerations

• Also got registered to work in MEMS lab

Email reply from Fan

• Joel and I have been thinking that jumping to chip on PCB packaging will be much eaiser to implement bc we can reduce the complexity and number of process steps in packaging manufacturing

• we should be able to cover up the chip with lower risk of contamination by 3D printing a cap that is much larger than the chip itself and screw mount to through holes on the board

• I don't think this will change anything on EDA's side but ran it by Icey to check

Struggles:

• making enough time for packaging due to time spent on school work and trying to make ALD deadlines

To do this week:

• work on presentation

• should be able to start PCB design once we get the thumbs up from Icey and EDA team

  • need to get footprint of analyzer connector

  • create footprint for wire bond pad pattern

  • consider things like decaps for the board...?

• hoping to mill the board this weekend and be ready for resistor lab chip to be made

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Weekly Update #3:

ALD:

• Ordering for sealing unused section:

Item	Quantity	Cost
1/2" VCR face seal metal gaskets	4	$ 8.80
1/2" Plug VCR Face Seal Fitting	1	$ 15.80
1/2" Cap VCR Face Seal Fitting	1	$ 33.60

• Planned out rough cutout locations for delivery storage

• Created rough CAD for delivery storage

  • Have a rough concept for fixturing the manifold by holding onto the unused section

  • 
  • 

• Had a rough week with school work so challenge has been to get good progress on CAD :(

• Planning to get the design to have finalized dimensions and complete for manufacturing this week

  • Need to add concept for holding the bottom of ampules as well

    • will have to think a lot about how tool access will be like given limited space

  • Really hoping to make the Friday ordering deadline for SendCutSend

  • Also need to double check dimensions of hardware and communicate with Viswesh to make sure that routing will be successful

Packaging:

• Worked with Icey and EDA team on plans for first package:

  • Will design and build a 16 pin DIP package for 2 major uses:

    • Wire bond resistance testing

    • MOSFET testing

• Wire bond test:

  • Basically a similar setup to resistor lab, except the N channel conduction path width is being varied in order to keep wire bond pad locations roughly similar

  • Will consist of multiple patterns on the chip for both yield issues and for testing different pad sizes for performance

    • Gave them at least 200um x 200um pads and 300-500um spacing

    • the package for resistance testing will be open top so we can wire bond to different patterns with varying pad sizes by snipping and rebonding after each CV test

  • 

    Credit: Sandra You

• MOSFET Testing:

  • will have 5 NMOS requireing 15 I/O and 1 GND

  • still in the planning and design stage but can use the same package as resistance testing

• Meeting notes:

  • collaborations between Metrology and EDA group:

    1. (Gina Seo and Sandra You) DRC provides Resistor lab pattern but with pads added on at the peripheral ( pad size > 200umx200um and 300um-500um spacing between pads)

    2. (Gongwei Wang) I/O information (numbers and types of pad for future circuit design, atm: 3 terminal MOSFET 16(5mosx3pads+1gnd) ),

    3. (James Lin) provides some footprints info, and a sketch of pad locations. Research on different IO pad structures.

• Things to do this week:

  • give EDA pad thickness to design for

    • Need to read over this: https://lnf-wiki.eecs.umich.edu/wiki/Wire_bonding#Design_considerations

  • Come up with a lead frame and encapsulation design

• Things I am struggling with:

  • having enough time to focus on this since am behind on ALD

  • Jaci sent me the wrong file so i have to keep waiting to get MEMS lab access 😭

  • also the ebay lead frame got rejected but it should be ok cuz we have to make our own anyways

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Weekly Update #2

ALD:

• Confirmed that current heating tape can be used and need programmable AC power supplies after some research

• Ordered 2 stage regulator for N2 tank: https://store.mathesongas.com/3120a-series-dual-stage-high-purity-regulator-brass/

• For CAD:

  • Made a table spaceclaim based on measurements in the lab to help the ALD team plan positioning and pipe routing

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  • Created a rough model of the ALD manifold to reference for mounting ideas

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  • Talked with Viswesh about possible concepts for supporting the ampules

  • Also considering just switching to AL sheet metal that is a bit thicker than what we have to do away with floppiness concerns - don't anticipate a huge increase in cost

• Currently trying to get CAD ready as soon as possible but currently a bit short on time to head down to lab frequently

• Over the next week I will be trying to get models of ampules and ALD valves in CAD so I can begin work on the enclosure and support structures

• Also need to get the heat tapes out and figure out how exactly we will wrap the manifold

Packaging:

• Currently in process of getting MEMS lab access and took a bit of time to know how to use the wire bonder with Joel

• Ordered some sample leadframes and PCB SMD breakout module

  • https://www.ebay.com/itm/256227046773

  • https://www.amazon.com/Custom-Circuit-Solutions-Integrated-Capacitor/dp/B09XLSY9GJ?source=ps-sl-shoppingads-lpcontext&ref_=fplfs&smid=A2I1FZB08726AV&gQT=1&th=1.

• Tentative decision is PCB mill for lead frame and resin 3D printing for encapsulation

• Confirmed that Ideate offers resin 3D printing and curing for students

• Had a meeting with Icey to discuss plans for working with packaging:

  1. @Gina Seo @Sandra You | EDA DRC provides Resistor lab pattern but with pads added on at the peripheral ( pad size > 200umx200um and 300um-500um spacing between pads)

  2. @Gongwei Wang I/O information (numbers and types of pad for future circuit design, atm: 3 terminal MOSFET 16(5mosx3pads+1gnd) ),

  3. @James Lin [ALD] [Packaging] provides some footprints info, and a sketch of pad locations. Research on different IO pad structures.

• Also got info from Jay that we may need packages for 2 terminal devices

• Going forward I will be looking into possible packages to reference for the resistor lab pattern and 5 MOS pattern and start thinking about how best to distribute pad locations

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Weekly Update #1

ALD:

1MB

James Lin ALD Project Proposal.pdf

pdf

• Got my project proposal for precursor delivery system finished and received feedback on it. Will be waiting on revision from my lead later this week.

• Over the upcoming week I will focus on getting the remaining components for delivery system ordered (KF25 tube fitting, 2 stage regulator, heating tape). Hopefully by Tuesday. I will also find time to figure out the physical design space for the ALD system in our lab in so I can make a general space claim in CAD.

• I'm currently trying to figure out uncertainties with requirements for heating tape and what option would be best for our controls team to interface with. I've added some links in the master doc from this preliminary research.

Packaging:

505KB

James Lin Packaging Project Proposal.pdf

pdf

• Got my project proposal for IC packaging finished and received feedback on it. Will be waiting on revision from my lead later this week.

• I will be working with Joel to get familiarity with the wire bonder in the upcoming week. I will also start picking a suitable package for the planned 1cm x 1cm chip size,

• Currently I'm trying to narrow down manufacturing methods for the lead frame and encapsulation

  • Lead frame:

    • TechSpark has confirmed that we cannot use their laser cutter for copper,

    • Joel said that he has seen people using the CNC mill for this, so I will be waiting on details regarding that.

  • Encapsulation:

    • 3D printing seems like an attractive option due to high resolution and low complexity.

    • Joel said that we can set up the resin printer in his office.

    • I also know that IDEATE does resin printing but need to go down there to confirm availability for non IDEATE students.

    • Still a bit concerned about whether 3dp material can withstand soldering, but there might be workarounds like using sockets

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Weekly Update #0

ALD:

• I went through the primer and documentation to understand the basics of the project. I selected the delivery system as my main project for the semester. Current struggle is going to be tracking down CAD that was previously done for the project. I plan to read more into the specific design requirements for the delivery system and look through the CAD to understand what models of existing parts I will need to source/create.

Packaging:

• We started with a rough idea to build our own wirebonder, but after the meeting with Icey from the CMOS team, we decided that using the exisiting one in the MEMs lab is sufficient for this semester. So instead I will be working more on a solution to package our silicon chips for this semester. After talking to Joe, we decided to start by purchasing lead frames for testing and we are having trouble finding a complete DIP package that we can buy online.

• Link to DIP lead frame on ebay: https://www.ebay.com/itm/256227046773

• Some notes from Friday's meeting with Icey:

  • pads will be done with thermal evaporator - has AL capacity

  • we should watch out for resistance at connection

  • at MEMs lab pads are 200umx200um (larger is reccomended), need at least 300um-500um ish between each pad

  • our chips are currently 1cmx1cm

  • bond wires can extend to a few cm long

• Going forward I will look into different options for packaging (pads on PCB or attempt to replicate DIP package from industry) I will also start to explore manufacturing methods and some design requirements for our IC package.